Co cation effects on activity and stability of isolated Pd(II) cations in zeolite matrices for selective catalytic reduction of nitric oxide with methane

Masaru Ogura*, Susumu Kage, Tomoko Shimojo, Junko Oba, Masayoshi Hayashi, Masahiko Matsukata, Eiichi Kikuchi

*この研究の対応する著者

研究成果: Article査読

32 被引用数 (Scopus)

抄録

Palladium ion-exchanged zeolites (ZSM-5, mordenite, ferrierite, Y, beta) were tested to evaluate catalytic activity for selective reduction of nitric oxide with methane (CH4-SCR) and stability in the presence of 10% water vapor at a relatively high temperature of 500°C. Deactivation of the catalytic activity was inevitable on Pd/HZSM-5 with a Si/Al ratio of 19.8 under the reaction conditions. When the Si/Al ratio decreased, the durability was slightly enhanced. Among the zeolites tested, palladium supported on mordenite showed stable NO conversions. The addition of cobalt effectively stabilized the activity of Pd-H-zeolites, particularly with the addition of 3.3 wt% cobalt onto Pd/HZSM-5, of which no deactivation was noticeable for at least 50 h. Isolated Pd2+ cations on HZSM-5 were the active and selective sites for CH4-SCR. The isolated Pd2+ cations could not be exchanged by Na+ cations in NaCl titration test after the addition of 3.3 wt% cobalt, while NH4NO3 titration revealed that the isolated Pd2+ existed in the sample. This means that Co2+ changes the ion-exchange property of the isolated Pd2+, leading to a much higher stability than Pd/HZSM-5 with regard to durability. The effect of Co2+ on the stability of the isolated Pd2+ cations and their sitings in zeolite cavities is discussed.

本文言語English
ページ(範囲)75-84
ページ数10
ジャーナルJournal of Catalysis
211
1
DOI
出版ステータスPublished - 2002
外部発表はい

ASJC Scopus subject areas

  • 触媒
  • 物理化学および理論化学

フィンガープリント

「Co cation effects on activity and stability of isolated Pd(II) cations in zeolite matrices for selective catalytic reduction of nitric oxide with methane」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル